What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

RV-10 Main Gear Vibration

Dave'sRV

Member
Patron
I have moderate to severe main gear vibration when slowing between 40 and approximately 20 knots. Some posts have suggested wood gear leg stiffeners like I had on my 6a. Has anyone done this and what were your results? If these work, where would I buy them. Also, I have Air Trac 6x6 tires. There has been some discussion on round vs flat tread. Has anyone had trouble with these tires?
Thanks for the help,

Dave
 
Yup

Strasnuts here in Utah did it and saw some improvement but I think there are things he feels to make it even better.
But it sounds like yours is no different than all of ours. Same speed range.
Someday there will be a very nice design to fix this.
 
Same issue here. I just use the brakes to take the speed down below shake speed. I figure a little wear on the brakes is better than the gear shaking.
 
Just CURED THAT PROBLEM in the six this past weekend!

Soooooo... Billy's Six has been having a main wheel shimmy on both main wheel for about the last 10 hours. The plane has 110 hours on it and it has gotten really bad.

We decided to look into it a bit more deeply. We balanced the tires using tape-a-weights and it improved a bit. It took a fair amount of weight. Probably about 3-4" of weights on each wheel!

After a test flight, I saw only a slight improvement. The shimmy was the worst between 14-34 knots either decelerating or accelerating.

The tires are out of round and I was wondering if that was contributing to the problem in any way.

Billy suggested lowering tire pressure. We brought the tires down to about 26 lbs and it was like MAGIC! ALL the shimmy was gone!

I guess that the additional rolling friction with the lower tire pressure reduces the ability of the wheel to speed up and oscillate in a fore and aft motion.

Perhaps when the tires were newer and less egg shaped this didn't matter as much but now that they are older...

Soooo, if this helps anyone out there... That is why we are here!

:cool: CJ
 
Just CURED THAT PROBLEM in the six this past weekend!



............The tires are out of round and I was wondering if that was contributing to the problem in any way.



Soooo, if this helps anyone out there... That is why we are here!

:cool: CJ

Years ago, before radials tires, we had our tires "shaved" until they were perfectly round and they rode very well.

Seems that it would be easy to mount the tires in a balancer and use a grinder of some sort, to true the tires, no?

Best,
 
Pierre,

Yes, we were going to persue a fix lie that if the change in pressure was unsuccessful.

As things turned out... No need!

I am VERY PLEASED with the rollouts and taxi handling once again!

:D. CJ
 
Gear Shimmy

As Scott stated I had the gear shimmy at 25-32 kt range. It was pretty bad on mine with stock tires. It became even worse when I installed the wheel pants and fairings. I had to fix mine so I made wood gear leg stiffeners out of Oak. I prosealed them to the back of the gear leg and spiral wrapped fiberglass tape around them. They fit inside the fairing and are tapered and triangular in shape. I noticed a huge difference and noticed only a very slight to sometimes NO shimmy. I tried less air and more air and noticed a difference with more air. I now have 50 psi per side and gear leg stiffeners and absolutely no shimmy. I have spoke to others about different materials to use for stiffening the gear but you don't want to transfer gear flex to the fuselage. You need to use material that will flex enough but change the resonance of the shimmy. Oh ya, I have 290 hours and original tires and tubes, tires rotated to other side once. I have never balanced my tires.

my .02
 
Lucke me

I guess I am just lucky but I have never noticed any gear shimmy.
135 hrs so far and just rotated the original tires at first annual.
Just wondering if there is anything different on my installation or anything different with your installations.
After reading all the shimmy reports I have been expecting some sort of shimmy but none so far, not in any loading condition or any tire pressure condition.
I have the beefed up wheel pant mounting extensions but nothing else added otherwise.
 
Hmmm, I believe Tim Olson never had gear shimmy either. I almost left out, I installed PlaneAround wheel fairing spacers too:)
 
Gear shimmy

I too have the gear shimmy problem although it seems not to be as bad as some others have described. I did balance the tires and that seem to help a little bit but not much. I then experimented with tire pressure and found that by increasing the pressure that would lower the speed at which the shimmy would occur. in the end I have settled on 55lb. in the mains and 45lb. in the nose.
This configuration has not eliminated the problem but reduced it in severity because of the lower speed at which it occurs. A light tap on the brakes will immediately stop the shimmy and while I would like to eliminate the problem all together I have learned to live with it for now until a well tested fix has been found.
As for the 26lb tire pressure suggested in a post above. With the airplane full of fuel it would be impossible for me to push my airplane back into the hangar by my self.
 
I run tire pressure 10 psi higher than Van's recommended pressures. If mine sits more than two weeks the tires get flat spots and cause shimmy during taxi, especially solo. If taxiing with morning sun shining across nose pant, I notice a fore-aft shimmy around 15 kts. I fly at gross and near aft limit 95% of the time and rarely have any shimmy. My original tires are 1/4-5/16" out of round, so I did not bother balancing.
 
Egg Shaped

If your RV sits longer than about a week your tires will be egg shaped no matter how round or balanced they were at one time.
Unless you suspend your aircraft in your hangar, there is simply no point in balancing your tires or shaving them to be round.
 
Just CURED THAT PROBLEM in the six this past weekend!

Billy suggested lowering tire pressure. We brought the tires down to about 26 lbs and it was like MAGIC! ALL the shimmy was gone!

You may consider carrying a spare tube, the biggest cause of flats on tube type tires, in my experience, is from under inflation. Even though 26 psi isn't grossly low you are inviting trouble.
 
For those of you who have tried the balancing methods and lower tire pressures with no success, we do sell gear leg stiffeners which fiberglass to the rear of the gear legs inside the fairings. They are made of wood, cut and tapered to fit on the back of the gear legs.

We don't manufacture these in house. Another RV builder makes them for us, and we resell them for him.

Take a look at our website in the RV section, and you will find the gear leg stiffeners .
 
You may consider carrying a spare tube, the biggest cause of flats on tube type tires, in my experience, is from under inflation. Even though 26 psi isn't grossly low you are inviting trouble.

Walt, thanks and yes we do carry a spare tube just as a matter of course.

Besides... With the greaser landings that I do it just isn't an issue! Hahaha

:D. CJ
 
For those of you who have tried the balancing methods and lower tire pressures with no success, we do sell gear leg stiffeners which fiberglass to the rear of the gear legs inside the fairings. They are made of wood, cut and tapered to fit on the back of the gear legs.

We don't manufacture these in house. Another RV builder makes them for us, and we resell them for him.

Take a look at our website in the RV section, and you will find the gear leg stiffeners .

Are these stiffeners sized correctly for the RV-10 main gear?
 
Are these stiffeners sized correctly for the RV-10 main gear?

David....

They are notched in the back in a triangular shape. So, they will fit over any round gear leg.

We don't manufacture these in house. They come from another RV builder who has been making these for RV aircraft for years.

Feel free to contact us at [email protected] if you would like me to take any specific dimensions for you.

Steve
 
No shimmy here

I guess I don't have the shimmy -- I sure haven't noticed it. Stock tires, planearound brackets on the wheel, I did balance the wheels/tires, 230 hours on the plane. I did get a nose wheel shimmy early on but it is way down after I retorqued the nose wheel nut to take up the looseness that had developed. I'll have to pay more attention in that speed range for the main gear shimmy, but I sure haven't noticed anything objectionable. As for flat spots, my plane hasn't sat for more than 1 week :) so I can't speak to that.
 
Years ago, before radials tires, we had our tires "shaved" until they were perfectly round and they rode very well.

Seems that it would be easy to mount the tires in a balancer and use a grinder of some sort, to true the tires, no?

Best,

....We offer this service, Truing, Balancing, Rotor Truing and ball bearing conversions for all wheels (mains and nose) on all models. Check out the videos on this at our web site. Thanks, Allan...:D
 
landing gear mount and landing gear leg

Hi
I had very bad vibration in my rv-10. Enough that i decide to stop flying until i find the problem . I already have balance all the tires, change for the plane around bracket for the wheel pant but it was worst and worst. Really bad.

I decide to change all the 3 tire for good year custom III. I already check if there was some loose in the gear leg before with the tire on. This time, i jack the plane and remove tire to put the new one. I have try to move the gear leg again. Nothing until i put a fair amount of rotation force and then, it move significantly. I check the bolt that atach the main gear leg and landing gear mount. I was almost able to rotate the bolt by hand. The nut was moving too. It look like it bottom out. I add a second washer and torque it. Did de same for my other main landing gear.

The flight today was really great. Almost no vibration. No shimmy !!.

I am afraid it is only a temporary fix. So i will order close tolerance bolt and reamer and if it just begin to vibrate again, i will put these close tolerance bolt ( or i will put them anyway at my annual in 5 month. )

Lan Vinh Do

( should have put the torque wrench at the last annual!!)
 
Stiffeners

I don't know why nobody believes what Van says about the round gearlegs but here is some info. Anybody interested in stiffeners contact me ([email protected]) or Steve (in previous posts here) and we'll be happy to accomodate. Running the tires soft works in some situations but you will wear them out really fast. We run our planes with max tire pressure listed on the sidwall.
The gear leg stiffeners that I am making are the ones that Van?s suggests in his plans. Being a cabinetmaker, I found that what I make easily has been a burden to other builders. The stiffeners work on any round, steel gear leg. They are designed to eliminate vibration and oscillilation caused by the round shape of the steel gearlegs. The stiffeners are constructed of Pine, tapered and beveled to fit under Van?s standard fairing. Take it from me, they make a tremendous difference. I?ve had it both ways, I know! A side benefit is less springback (bounce) if you should flare a little too high on landing. (Of course none of us ever do that)

After installing one of my modified stiffeners on my 6A?s nose gear, I can highly recommend putting a stiffener here as well. I found that there was significantly less vibration on taxiing with a stiffener installed.
 
You can add one more to the list to try. Not flying yet but hopefully this summer. PM me with the info on getting a set.

Thanks
Brian
 
Stiffeners

As my post states on Page 1, they really made the difference on my 10. I would have bought them instead of making them if they were available at the time. I'm sure the pine material works great and is what Van's recommends. I made mine from Oak.
 
Picture of wood stiffeners

I've heard a lot of discussion about these wood stiffeners, but I've never seen any pictures. I have a hard time visualizing them. Could someone please post a picture.

Thanks
 
Rotating torque on mains

There is a guy who posts here, that has a great video showing the effects on the mains during touch down...very interesting.
He just recently offered a straight trade for his Garmin 650 for my 430...so i need to be careful i don't jeopardize the deal by identifying him.:D He may share on his terms.
 
There is a guy who posts here, that has a great video showing the effects on the mains during touch down...very interesting.
He just recently offered a straight trade for his Garmin 650 for my 430...so i need to be careful i don't jeopardize the deal by identifying him.:D He may share on his terms.

You might be referring to this:

http://s626.photobucket.com/albums/...iew&current=20130201Landings1_zpsf3d1c36e.mp4

However, the shimmy I keep hearing about is at lower speeds, taxi usually. I had to keep rolling on those flights due to another guy in the pattern.

And as I recall, YOU offered to trade your 430 for my 650 :)
 
Thanks Bryan

Look at 4:18...the twist on the landing gear....even though this pilot has a habit of greasing them in. This may be what caused Lan Vinh Do's issue?

Back to looking for a 650....Never a deal till both parties agree and exchange.:D

And 9:05-9:08
 
Last edited:
I see what you are referring to, but I don't see it as a twist, more of a flex as the tires touch and the slight resistance to get them turning. The consensus on the original post was that it is a harmonic vibration issue that occurs at low speeds. We want them to flex, we just need to figure out a way to adjust the speed at which they shudder/shimmy. Anecdotal info seems to indicate that the gear braces help.
 
Maybe my vibration was worst

Hi
I agree with everybody but i think i had a very BAD vibration. The one that you think that the airplane will fall apart or the one that make you inspect the engine mount and firewall because you would expect to find a crack.
I had a rv-7 before and i had some vibration that i was able to deal with but in the rv-10 it was bad. It begin with just a little shimmy like in my rv-7a but went worst and worst to very BAD.

With my upper gear leg bolt loose, with time, i think i would have a structural failure. I just want rv-10 owner to check these bolt if they have bad vibration.
It was hard to notice when moving the gear leg when the airplane was on jack but it was there. Not forward and backward movement but rotation.

Now i can live with the really small vibration that i have. I may add stiffener if it bother me but i don't think it can do anything to my airframe now.

So in conclusion, I don't say that i found the vibration problem of all the RV but i found mine and i am glad because i am sure it would be dangerous with time.
 
For those of you who have tried the balancing methods and lower tire pressures with no success, we do sell gear leg stiffeners which fiberglass to the rear of the gear legs inside the fairings. They are made of wood, cut and tapered to fit on the back of the gear legs.

We don't manufacture these in house. Another RV builder makes them for us, and we resell them for him.

Take a look at our website in the RV section, and you will find the gear leg stiffeners .

Just installed these stiffeners and it made a HUGE difference. No more main gear shake.

Has anyone installed a nose gear stiffener? I?m getting a little shaking on roll out out of the nose gear.
 
Back
Top